nvdimm/btt: Handle preemption in BTT lane acquisition
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 6.1.178, 6.6.145, 4.20, 5.5, 5.11, and 5 more
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
- Exploitation: none
- Automatable: no
- Technical impact: total
Summary
In the Linux kernel, the following vulnerability has been resolved: nvdimm/btt: Handle preemption in BTT lane acquisition BTT lanes serialize access to per-lane metadata and workspace state during BTT I/O. The btt-check unit test reports data mismatches during BTT writes due to a race in lane acquisition that can lead to silent data corruption. The existing lane model uses a spinlock together with a per-CPU recursion count. That recursion model stopped being valid after BTT lanes became preemptible: another task can run on the same CPU, observe a non-zero recursion count, bypass locking, and use the same lane concurrently. BTT lanes are also held across arena_write_bytes() calls. That path reaches nsio_rw_bytes(), which flushes writes with nvdimm_flush(). Some provider flush callbacks can sleep, making a spinlock the wrong primitive for the lane lifetime. Replace the spinlock-based recursion model with a dynamically allocated per-lane mutex array and take the lane lock unconditionally. Add might_sleep() to catch any future atomic-context caller. Found with the ndctl unit test btt-check.sh.
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: none · Automatable: no · Technical impact: total
- Record last updated
Affected versions
- Linux Linux
From f23859748e3d530217b197e146a9ac84faf0a282 · fixed in fd7a97b2514cfc4b4cc067a27dd39bde2a8b1735; From 6f50b414f1a0d790f11a6438a3ad6d0577eb2c18 · fixed in 73e35c1bdfa160b41fdbe204e02325f0687de506; From 36c75ce3bd299878fd9b238e9803d3817ddafbf3 · fixed in 417918783bcfe0be135019df16a267b3af442efd; From 36c75ce3bd299878fd9b238e9803d3817ddafbf3 · fixed in 5c53406098b599c420b031e6ec5ba8a2f3794c50; From 36c75ce3bd299878fd9b238e9803d3817ddafbf3 · fixed in 4eafa810b042d985ec6bbf5b514414e73cee6f6f; From 36c75ce3bd299878fd9b238e9803d3817ddafbf3 · fixed in 8d4b989d9c9afe5f185aa5853b666fc4617afe9e; From 6.1.63 · fixed in 6.1.178; From 6.6.2 · fixed in 6.6.145; From 4.19.299 · fixed in 4.20; From 5.4.261 · fixed in 5.5; From 5.10.201 · fixed in 5.11; From 5.15.139 · fixed in 5.16; From 6.5.12 · fixed in 6.6
- Linux Linux
6.7
- KernelLinux
fixed in 6.1.178; From 6.2.0 · fixed in 6.6.145; From 6.7.0 · fixed in 6.12.97; fixed in 6.18.40; From 6.13.0 · fixed in 7.1.5